Signaling the location of underwater wells

ABSTRACT

Method and apparatus for use in locating the position of underwater wells involves a signal emitter adapted to be propelled through a flow line to a selected point proximate a wellhead where it signals the location of the well for such purposes as establishing the vertical re-entry point of the well for workover rigs.

United States Patent 91 Brasier [451 Feb. 11,1975

1 1 SIGNALING THE LOCATION OF UNDERWATER WELLS [76] Inventor: Charles A.Brasier, 4508 Wade Dr.,

Metairie, La. 70003 [22] Filed: May 29, 1969 2 1 Appl. No.: 828,925

[52] US. Cl. 340/5 R, 166/65 R, 166/153, 166/156, 166/253, 18l/0.5 R,18l/0.5 A

[51] Int. Cl. H041) 13/02, E2lb 47/12 [58] Field of Search 166/65 R,253, 66, 77, 166/153, 156; l81/0.5 A, 0.5 P, 0.5 R; 340/5 [56]References Cited UNITED STATES PATENTS 4/1959 En Dean et a1, 340/18 NC1/1964 McStravick 4/1967 Yetman WORK-OVER VESSEL 3,401,749 9/1968 Daniel166/46 3,407,384 9/1968 Wiley 3,554,284 1/1971 Nystrom 166/250 OTHERPUBLICATIONS C. A. Brasier et al., Pump-Down Completion and WorkoverTechniques for Satellite Underwater Wells, ASME Publication 67-PET-40,July 13, 1967.

Primary Examiner-Maynard R. Wilbur Assistant Examiner-11. A. BirmielAttorney, Agent, or Firm-John S; Schneider [57] ABSTRACT Method andapparatus for use in locating the position of underwater wells involvesa signal emitter adapted to be propelled through a flow line to aselected point proximate a wellhead where it signals the location of thewell for such purposes as establishing the vertical re-entry point ofthe well for workover rigs.

4 Claims, 8 Drawing Figures PATENTEU H975 3,866,160

SHEET 10F 2 WORK-OVER VESSEL 1:1

INVEN'IOR.

CHARLES A. BRASIER,

kqgf Mm ATTORNEY;

PMEHTEUFEBI 1 I915 3.866.160

SHEEIZOFZ lh I; l: A 1

IHI

m m v i l INVENTOR.

CHARLES A. BRASIER, BY K ATTORNEY.

SIGNALING THE LOCATION OF UNDERWATER WELLS BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention relates to theproblem of locating underwater wells. More particularly, the inventionis directed to locating an underwater well having a flow line extendinginto the well from an accessible but remote point. More specifically,the invention is concerned with method and apparatus for employingthrough flow line techniques to run tools, and the like, in wells, andis particularly adapted to the use of such techniques in underwaterwells.

2. Description of the Prior Art Devices (such as acoustical beacons) areknown and used to mark and signal the location of underwater wells, sothat, for example, vertical re-entry can be made through the wellheadinto a well for workover operations. These signal devices, typicallyattached by divers at or near the well or wellhead, are continuouslysubjected to the rigors of the underwater environment, which acceleratesthe end of the useful life of their energy sources, usually batteries.This necessitates periodic replacement or maintenance of the signaldevice or its power source, a difficult operation that takes highlyexpensive manpower and seagoing equipment. As exploration for oil movesinto deeper and deeper waters, to the extent that divers are still ableto do these jobs, the costs will get even dearer, and known methods oflocating the underwater wellhead to protect the investment it representswill be inadequate.

SUMMARY OF THE INVENTION This invention overcomes the limitations andproblems associated with the deployment, protection and recovery ofknown underwater signal devices by making use of equipment usuallyalready on site with techniques now in the hands of producers of oilfrom subsea locations. It has as its purposes and objects the provisionof apparatus and method that not only is useful for locating theposition of an underwater well, but further, permits installation,retrieval and change of underwater signal devices without the use ofdivers or remote manipulators. In addition, it provides an underwatersignaling device which is not subjected to the ocean environment. Aspecial feature of the invention is that it enables one signal source tobe used to serve several wells, thereby reducing the number of sourcesneeded for that purpose.

Briefly, these and other objects of the invention are accomplished by asignal emitter adapted to be propelled to and from a selected point in aconduit forming a passageway extending from an accessible remote placeinto an underwater well having a wellhead. The selected point in theconduit is proximate the wellhead. In one aspect, the conduit is curved,and either fluid pressure or mechanical force originating externally ofthe conduit is exerted against the signal emitter to propel it throughthe conduit. When the signal emitter is adapted for fluid pressurepropulsion, at least a portion of the signal emitter is shaped to closethe annulus between it and the inner wall of the conduit sufflciently topermit it to be pumped through the conduit to the selected point in theconduit. By inserting a signal emitter adapted to be propelled through aconduit forming a passageway extending into an underwater well from anaccessible remote place, and then by moving it through the conduit to apredetermined point in the conduit proximate the wellhead of thatunderwater well, one is enabled to signal the precise location of thatwell.

BRIEF DESCRIPTION OF THE DRAWINGS Forms in which the invention may beembodied are shown in the drawings accompanying and forming part of thepresent specification. Referring to the drawings:

FIG. 1 is a schematic view of a well completed off water bottom showingcurved conduit extending into a wellhead;

FIG. 2 is a side elevational view of a portion of conduit remote from anunderwater wellhead, with a portion of the conduit broken away to reveala signal emitter in passage;

FIG. 3 is a side elevational view of a portion of a Christmas tree at anunderwater wellhead, with a portion ofa conduit extending into thewellhead being broken away to show a signal emitter which has been runinto place;

FIG. 4 is a schematic view of a well completed on water bottom in whichcurved conduit extends into a wellhead;

FIG. 5 is a view in vertical longitudinal section of a portion ofconduit carrying a mechanically propelled signal emitter in transit;

FIG. 6 is the same view as FIG. 5, but showing a signal emitter beingmoved by fluid pressure;

FIG. 7 is a side elevational view of a signal emitter of this invention;and

FIG. 8 is a schematic top plan view of a conduit system in which thepresent invention may be employed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The forms shown in the drawingswill now be described in detail for the purpose of illustrating how thegeneral principles of the invention may be carried out.

Referring now to the drawings, in which identical numerals identify likeparts in the various embodiments, and in particular to FIGS. 1 and 4,reference numeral 10 indicates the surface of a body of water 11 inwhich an underwater well generally indicated by reference numeral 12 iscompleted. In FIG. 1, underwater well 12 is completed at a wellhead 13on a submerged platform 14 off water bottom 15. In FIG. 4., underwaterwell 12 is completed on water bottom 15 A well casing 16 is arranged inthe underwater well and cemented into place by the usual techniques.Attached to well casing 16 by flange members or connectors 17 is awellhead Christmas tree 18 which is closed at its open end by flangedmember or connector 19. It will be noted that the well 12 is completedsubstantially below water surface 10.

Connected to the Christmas tree 18 are a plurality of curved flow linesconduits 20 and 21, whose passage into the Christmas tree is regulatedby wing valves 22 and 23. Flow lines 20 and 21, which are interconnectedabove wing valves 22 and 23 by a bypass valve 24, connect respectivelyto tubing or pipe strings 25, 26 which extend into the well to one ormore hydrocarbon productive strata (not shown) from which oil and/or gasmay be obtained or into which fluids may be injected. The tubing strings25, 26 may suitably be interconnected at one or more points intermediatetheir end for workover operations and the like. Flow lines 20 and 21extend into well 12 from an accessible remote station, such as thesupport platform 27 which may be grounded on bottom by suitablestructure as illustrated in FIG. 4, or an onshore site 28 as illustratedin FIG. 1.

In FIG. 1, flow lines and 21 are terminally closed with suitableremovable covers 29. A line 30 provided with suitable valves connects apump 31 into flow lines 20 and 21. Pump 31 is connected to a source offluid 32 by means of a line 33. That fluid may suitably be oil producedfrom strata underlying water bottom 15. Similarly, in FIG. 4, lines 20and 21 are adapted to be connected by valve controlled line 30 to a pump(not shown). Fluid can pass from a source 32 into lines 20 and 21 undercontrol of valved lines 34. Lines 20 and 21 have valves on both sides ofthe inlet from line 30. In addition, platform 27 is provided with a pipereel 35 onto which is wound a continuous length of substantiallyinflexible tubing 36 (tubing which will support its own weight). Tubing36 feeds off pipe reel 35 across straightening rollers 37 (such asdescribed by McStravick in US. Pat. No. 3,116,793 issued Jan. 7, 1964)through an adapter 38 into flow line 21.

A signal emitter 40 adapted to be propelled through a flow line conduit,in accordance with this invention, is illustrated in FIG. 2. A housing41 encloses a sonic pinger or radioactive source or an electrical highfrequency transmitter. Housing 41 is fitted with a piston 42 closing theannulus between the inner wall of flow line conduit and the housingsufficiently to permit the signal emitter to be pumped through the flowline by fluid pressure exerted against the piston. Another way in whichsignal emitter 40 is adapted to be pumped through a flow line is shownin FIG. 6. The signal emitter 40 may be carried by a tool or locomotiveassembly 43 constructed for movement in a flow line. In the formillustrated, the signal emitter housing 41 is secured to a locomotiveassembly 43 comprised of a series assembly of two-way pump cups 44 and45 closing the interior of flow line 20 sufficiently to permitlocomotive assembly 43 to be pumped therethrough. The pistons employedon signal emitter 40 and locomotive assembly 43 may suitably bestructured with ball valve passages as known to the art. The housing 41of the signal emitter 40 may have nonclosure runners or slides 46 todecrease wobbling or prevent jamming of the emitter housing duringpassage. The piston 42 of the signal emitter 40 in FIG. 2 mayincorporate the whole length of the housing to provide this protection.The fluid pressure exerted against signal emitter 40 or locomotiveassembly 43 to pump the signal emitter through flow line 20 is suppliedby the action of pump 31.

In addition to the pumpdown methods of delivering a signal emitterthrough a conduit to a predetermined site, mechanical force originatingexternally of the conduit may be exerted on the signal emitter toaccomplish the same result. As shown in FIGS. 4 and 5, a signal emitter40 is adapted to be propelled through flow line 20 by the feed of thecontinuous length of tubing 36 from pipe reel 35 across straighteningrollers 44.

Loops presently formed in two-inch flow lines have a typical diameter ofabout 5 feet, and the length of any cylindrical segment moved throughsuch flow lines is limited to about 8 to l0 inches. Various levels ofpower may be needed to drive the circuitry of different signal emitterstransmitting radio frequencies, yet space limitations may limit the sizeof the power source that can be contained in the same housing with thecircuitry. However, as illustrated in FIG. 7, the signal emitter may bemade up of a segment 47, containing the signal generating circuitry,electrically linked by a flexible coupling 48 to another segment 49,containing one or more power sources. Segment 49 may be connected by aflexible coupling to another segment carrying a power source, and inthis way, any desired level of power to drive the signal generatingcircuitry may be obtained.

The preselected point in the conduit to which the signal emitter ispropelled is proximate the wellhead of well 12. Most advantageously,where the wellhead is fitted with a Christmas tree, as illustrated inFIGS. 1 and 4, the wing valves 22 and 23 may be closed, the bypass valve24 opened, and the signal emitter of FIG. 3 or locomotive assembly andsignal emitter of FIG. 4 pumped down to lodge at the site of the wingvalve 22 in the flow line 20. Generally, the task of locating there-entry point of the well, which is the wellhead, is lessadvantageously served by placing the signal emitter below the wellhead.However, in some instances, such as when the wellhead is a substantialdistance above water bottom (FIG. 1), it may be desired to locate thesignal source in the flowline at some distance intermediate the level ofwellhead 13 and water bottom 15, or in some instances, even adjacentwater bottom 15. This may be accomplished by propelling the signalemitter to the wellhead and then pumping the volume of fluid through theflow line which would displace a column of fluid whose height equals thedistance down the flow line from the wellhead which it is desired toplace the emitter. Alternatively, the tubing 36 driven by pipe reel 35may be employed to propel the signal emitter down the flow line to apreselected site adjacent the wellhead or between it and the waterbottom by measuring the length of tubing rolled off the reel into theflow line.

In the practice of the present invention, referring to the FIGS. 1-7inclusive, the position of an underwater well 12, and particularlywellhead 13, is made ascertainable by inserting a signal emitter 40adapted to be propelled through a flow line into such flow line, closingthe flow lines with covers 29, and propelling the signal emitter throughthe flow line to a selected point in the flow line conduit proximate thewellhead 13, where it operates to signal the position of the well.

As illustrated in FIGS. 1 and 3, signal emitter 40 has been pumped toChristmas tree 18 with wing valves 22 and 23 closed and the bypass valve24 open. A sonic pinger, a radioactive source, or a high frequencytransmitter in signal emitter 37 sends out signal which are picked up byan acoustical, radioactive or high frequency signal detector carried bya workover rig or the like riding on water surface 10.

To retrieve the pumped down locomotive assembly and sonic emitter, thewing valves 22 and 23 are maintained closed and bypas valve 24 is keptopen. Fluid is pumped down through the flow line 21 to reverse circulateflow between flow lines 21 and 20 and thereby pump signal emitter 40through flow line 20 from the Christmas tree 18 on the wellhead 13 tosupport platform 27 or onshore site 28, where the signal emitter may beremoved from line 20.

The emitter delivered to site by tubing 36 is retrieved by withdrawingthe tubing to which the emitter is attached. Alternatively, if thetubing has already been withdrawn, a grabber" tool may be run down theflow line and attached to the emitter by pump or mechanical action andretrieved by pumping or by retrieval of tub- As illustrated in FIG. 8,the signal emitter of the present invention may be utilized to locatethe positions of a selected one of a plurality of horizontally spacedun' derwater wells 50, 51, 52 and 53. Each ofthe underwater wells hasconventional wellheads (not shown) mounting therein at least two pipestrings (e.g., 50a and 50b in well 50). These two pipe strings areinterconnected at some point along their length, such as adjacent theirlower ends. Each of the wells 50, 51, 52 and 53 is connected into asingle flow line circuit that is normally underwater except at anaccessible remote platform 54, where the flow line circuit starts andends.

The flow line circuit is made up of fluidly communicating conduits 55,56, 57, 58, 59, 60, 61, 62 and 63, which form fluid passageways. In theflow line circuit, flow line conduits 55 and 56 each extend from theremote platform 54, where they are accessible, to connect, respectively,with an interconnecting pipe string in underwater wells 50 and 53, e.g.,pipe strings 50a and 53a. The other interconnecting pipe strings ofwells 50, 53 and the interconnecting pipe strings of wells 51, 52 aresuccessively fluidly interconnected by underwater flow lines 57, 58 and59. Flow line 57 interconnects pipe string 50b (interconnected with pipestring 50a) with pipe string 51a; flow line 59 interconnects pipe string51b (interconnected with pipe string 51a) with pipe string 52a; and flowline 58 interconnects pipe string 52b (interconnected with pipe string52a) with pipe string 53b, interconnected with pipe string 53a. One orboth of the pipe strings connected into the flow line circuit may becontrolled by means of valves, in the manner disclosed in Ser. No.604,670, filed Nov. 21, 1967 for Thomas W. Childers and Edmond R. Genoisand having a common assignee with the present application.

Bypass flow line conduits 60, 61, 62 and 63, respectively proximate eachof the wells 50, 51, 52 and 53, interconnect, respectively, flow lineconduits 55 and 57, 57 and 59, 59 and 58, and 58 and 56. Admission offluid into any of bypass conduits 60, 61, 62 and 63 or into the pipestrings of wells 50, 51, 52 and 53 is controlled by a flow path diverterswitch, constructed, for example, after the teachings of US. Pat. Nos.398,836; 904,414; 3,206,140; and 3,410,501. The flow path diverterswitch is placed proximate either or both entrances of the bypassconduit at all wells, for example, at one of the connection unionsbetween a bypass conduit and one of the flow path conduits, asillustrated in FIG. 8, in which the flow path diverter switches areenumerated 64, 65, 66 and 67. Placement of the diverter switch at theleft entrance to the bypass conduit, as illustrated in FIG. 8, permitsclockwise flow through the flow line circuit. Conversibly, placement ofthe diverter switch at the right entrance to the bypass conduit allowscounter-clockwise flow. Diverter switch installation at both entrancesof the bypass conduit enables the operator to use both clockwise andcounter-clockwise flow. Each of the bypass flow lines 60, 61, 62 and 63is provided with a suitable foraminous stop 68, 69, 70 and 71,respectively, mounted therein to control (permit or prevent) passage ofthrough flow line tools through the bypass flow line while permittingfluid passage, therethrough. Compare, for example, the foraminous vaneof US. Pat. No. 3,261,048.

To establish a flow path to a position proximate a se lected well, allthe flow path diverter switches between the remote accessible platform54 and the flow path diverter switch of the well immediately past theselected well are actuated to establish a mandatory flow path into thebypass conduits from the platform 54 up to and inclusive of the bypassconduit of the selected well. All the bypass conduit stops between thediverter valve of the selected well and the remote platform 54 areopened and the stop for the bypass conduit of the selected well isclosed. For example, in FIG. 8, flow path diverter switches 64, 65 and66 are operated to divert flow into bypass conduits 60, 611 and 62, andbypass conduit stops 68 and 69 are opened while stop 70 is closed. Thus,a tool attaching or incorporating a signal emitter may be inserted intoremotely accessible conduit 55 and propelled by fluid pressure exertedon it, successively through conduits 55, 60, 57, 61 and 59 into conduit62, where it is lodged. By this manner, the position of a selectedunderwater well among a plurality of underwater wells may beascertained. Retrieval of the signal emitter may be effected by openingstop 70, switching diverter valve 67 into bypass conduit 63, and openingbypass conduit stop 71 to open a circuit for the emitter back toplatform 54.

The nature and objects of the present invention, having been fullydescribed and illustrated, what id claimed is:

I claim:

1. A method of locating the position of a selected underwater well amonga plurality of horizontally spacedapart wells, each having an underwaterwellhead and at least two interconnected pipe strings, each of saidwellheads being interconnected successively to another of said wellheadsby underwater conduits forming fluid passageways providing fluidcommunication from one well to another, at least two of said wellshaving a remotely accessible conduit fluidly communicating with aremotely accessible location, said remotely accessible conduits formingwith said underwater conduits a flow line circuit beginning and endingat said remote accessible place, said method comprising:

a. inserting a signal emitter into one of said remotely accessibleconduits; and

b. propelling said signal emitter through said flow line circuit to aselected position in said flow line circuit proximate said selectedunderwater well.

2. An apparatus for signaling the location of a selected underwater wellamong a. plurality of horizontally spaced-apart underwater wells, eachhaving an underwater wellhead and at least two interconnected pipestrings, each of said wellheads being interconnected successively toanother of said wellheads by underwater conduits forming fluidpassageways providing fluid communication from one well to another, saidapparatus comprising:

for each of at least two of said wells, a remotely accessible conduitextending :into the wellhead of such well from a remotely accessibleplace, said conduits of said wells forming with said underwater conduitsa flow line circuit beginning and ending in said remote accessibleplace, and

a signal emitter in at least one of said remotely accessible conduitsadapted to be propelled therecircuit proximate a second underwater wellin said circuit for location of said second well.

4. The method of claim 1 wherein said signal emitter is recovered from asecond of said remotely accessible conduits after traveling through saidflow line circuit.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 13,866,160 DATED 1 February 11, 1975 INVENTOR(S) Charles A. Brasier it iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the bibliographical data:

Exxon Production Research Add [73] Assignee:

Company, Houston, Tex.-

Signed and sealed this 24th day of June 1975.

(SEAL) Attest: C. MARSHALL DANN RUTH C. I'IASON Commissioner of PatentsAttesting Officer and Trademarks UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION PATENT NO. 1 3 6 1 DATED February 11, 1975 iNVENTOR(S) 3Charles A. Brasier it is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In the bibliographical data:

Add --[73] Assignee: Exxon Production Research Company, Houston, Tex.--

Signed and sealed this 24th day of June 1975.

SEAL) At t e S t 1 C MARSHALL DANN C. MASON Commissioner of PatentsAttesting, Officer and Trademarks

1. A method of locating the posItion of a selected underwater well amonga plurality of horizontally spaced-apart wells, each having anunderwater wellhead and at least two interconnected pipe strings, eachof said wellheads being interconnected successively to another of saidwellheads by underwater conduits forming fluid passageways providingfluid communication from one well to another, at least two of said wellshaving a remotely accessible conduit fluidly communicating with aremotely accessible location, said remotely accessible conduits formingwith said underwater conduits a flow line circuit beginning and endingat said remote accessible place, said method comprising: a. inserting asignal emitter into one of said remotely accessible conduits; and b.propelling said signal emitter through said flow line circuit to aselected position in said flow line circuit proximate said selectedunderwater well.
 2. An apparatus for signaling the location of aselected underwater well among a plurality of horizontally spaced-apartunderwater wells, each having an underwater wellhead and at least twointerconnected pipe strings, each of said wellheads being interconnectedsuccessively to another of said wellheads by underwater conduits formingfluid passageways providing fluid communication from one well toanother, said apparatus comprising: for each of at least two of saidwells, a remotely accessible conduit extending into the wellhead of suchwell from a remotely accessible place, said conduits of said wellsforming with said underwater conduits a flow line circuit beginning andending in said remote accessible place, and a signal emitter in at leastone of said remotely accessible conduits adapted to be propelledtherethrough to a selected position in said flow line circuit proximatea selected underwater well.
 3. The method of claim 1 wherein said signalemitter is propelled first to a position in said flow line circuitproximate a first underwater well in said circuit for location of saidfirst well, and then to a position in said circuit proximate a secondunderwater well in said circuit for location of said second well.
 4. Themethod of claim 1 wherein said signal emitter is recovered from a secondof said remotely accessible conduits after traveling through said flowline circuit.